Add comments app with models, views, and tests; integrate comments into existing models

reviews/models.py

@@ -1,6 +1,6 @@
 from django.db import models
 from django.urls import reverse
-from django.contrib.contenttypes.fields import GenericForeignKey
+from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
 from django.contrib.contenttypes.models import ContentType
 from django.core.validators import MinValueValidator, MaxValueValidator
 from history_tracking.models import HistoricalModel, VersionBranch, ChangeSet
@@ -40,6 +40,12 @@ class Review(HistoricalModel):
         related_name='moderated_reviews'
     )
     moderated_at = models.DateTimeField(null=True, blank=True)
+    
+    # Comments
+    comments = GenericRelation('comments.CommentThread',
+        related_name='review_threads',
+        related_query_name='comments_thread'
+    )
 
     class Meta:
         ordering = ['-created_at']